Refractory balls are spherical refractory materials made from industrial alumina and refractory kaolin as the main raw materials, through scientific formulation, forming, and high-temperature calcination. It is mainly used as an inert material in high-temperature industrial equipment such as ball hot blast furnace heat storage or methanol synthesis tower. According to their composition, they can be divided into high alumina balls, zirconia corundum balls, chromium corundum balls, etc., with specifications such as diameter 40, diameter 50, diameter 60, diameter 80, etc. Its thermal shock resistance is tested using the method specified in the industry standard YB/T4232-2010. After the 1990s, machine-made refractory balls gradually replaced handmade production. Transportation and storage require the use of ton bags and proper waterproofing.
It has 1 High mechanical strength and long service life; two Good chemical stability, no chemical reaction with materials; three Good high temperature resistance, the highest heat-resistant temperature of refractory ceramic balls can reach 1900 degrees. Especially suitable for high and low temperature converters, converters, hydrogenation converters, desulfurization tanks, and methane furnaces in fertilizer plants, it plays a role in dispersing gas-liquid and supporting, covering, and protecting catalysts. Refractory ceramic balls can also be used in hot blast furnaces and heating transformation equipment in the steel industry.
Physicochemical properties
Refractory balls have the characteristics of high mechanical strength, long service life, good chemical stability, no chemical reaction with materials, and good high temperature resistance. The highest heat-resistant temperature of refractory ceramic balls can reach 1900 degrees.
Some fire-resistant balls, such as cordierite insulation refractory balls, have low density, low mass per unit volume, low thermal conductivity, and good insulation effect.
The thermal shock resistance of fireballs is also one of the indicators that need special attention in quality control. The thermal shock resistance test shall be conducted in accordance with YB/T 376.3. According to YB/T 4232-2010 standard, the test shall be terminated when the crack width is greater than 1.5mm, or the crack width is ≤ 1.5mm and>1mm, and the length is greater than 30% of the circumference, or the crack width is ≤ 1mm and>0.5mm, and the length is greater than 50% of the circumference. The specifications of fire-resistant balls are divided into grades such as φ 40, φ 50, φ 60, and φ 80 according to diameter, and further divided into high alumina balls, zirconia corundum balls, chromium corundum balls, aluminum zirconium chromium composite balls, etc. according to composition.
Using mechanical forming methods to produce fire-resistant balls can increase their bulk density, strength, and service life.
Classification and Application
Refractory ceramic balls are divided into ordinary refractory balls and high alumina refractory balls. According to their composition, refractory balls can be divided into high alumina balls, zirconia corundum balls, chromium corundum balls, aluminum zirconium chromium composite balls, etc. Ordinary refractory balls are suitable for converters and converters in the sulfuric acid and fertilizer industries, while high alumina refractory balls are suitable for hot blast furnaces, heating converters, and other equipment in industries such as urea and steel. In addition, high alumina refractory balls (such as alumina ceramic balls) are also commonly used as inert materials in equipment such as methanol synthesis towers. In addition, there are also types such as cordierite that are heat-resistant and resistant to fireballs, which have the characteristics of low density and good insulation effect.
Preparation method
A preparation method for insulation and fireball resistance of cordierite, the raw materials of which include 45-50% cordierite, 15-20% aluminum ash, 8-10% talc powder, 10-12% sawdust, 1-3% binder, and the balance is clay powder in weight percentage. The refractory balls produced by this method have the advantages of good mechanical strength, low density, low thermal conductivity (saving more than 40% energy compared to traditional methods), low calcination temperature and short time.
Inspection method
The thermal shock resistance of fireballs is one of the indicators that need special attention in quality control, and its testing method is clearly specified in the industry standard YB/T4232-2010 "Refractory Balls for Ball Hot Blast Stoves".
The thermal shock resistance test shall be conducted in accordance with YB/T376.3, and the test shall continue when the crack width is ≤ 0.5mm. Terminate the test when one of the following conditions occurs: crack width>1.5mm; or crack width ≤ 1.5mm and>1mm, length greater than 30% of the circumference; Or crack width ≤ 1mm and>0.5mm, length greater than 50% of the circumference. Based on YB/T376.1, this method clarifies the criteria for determining resistance to fireballs and refines the length and width of cracks.
Storage and transportation
The requirements for the transportation and storage packaging of fireballs include using ton bags, ensuring waterproofing, meeting long-distance transportation needs, and indicating the factory name, product name, model, and weight. The packaging materials are not recyclable.
